Maize root length density and mycorrhizal infection as influenced by tillage and soil phosphorus

Abstract

Phosphorus added to soil in no‐till agriculture remains in the uppermost soil layer. Under conventional‐till age this stratification is not observed. This experiment investigated the effects of tillage and soil P on root length density (RLD), root hair growth, and mycorrhizal infection (VAM). Eight weeks after planting, plant and soil samples were taken to measure plant P uptake, soil extractable P, root parameters, and VAM. Our findings suggest that soil extractable P predominates as the factor most important in P uptake by maize. Tillage treatments affected the distribution of roots and the extractable P in the top soil layer. Soil depth significantly affected RLD, VAM, and soil P. The assumption that soil P would significantly alter root hair growth was not supported. The results of this field study are not consistent with the results of others based on pot or solution culture studies.

Key words:

• Root hairs
• conservation tillage
• vesicular‐arbuscular mycorrhizae